The present invention relates to an inkjet recording apparatus which ejects ink from a recording head to a recording medium and attaches the ink onto the medium, thereby performing the recording.
Conventionally, an inkjet recording apparatus, which ejects ink from a recording head to a recording medium and attaches the ink onto the medium, thereby performing the recording, has been known in the market.
In this conventional apparatus, a carriage to which the recording head is mounted reciprocates in a scanning direction, while the recording medium, such as a sheet of paper, is transferred in a direction perpendicular to the scanning direction. Positions of the recording head and the recording paper, as well as the ejection of the ink from the head, are controlled, so that the ink is attached to a specified position on the recording paper for recording. In this apparatus, a carriage driving motor, as a driver, reciprocates the carriage in the scanning direction, while a transfer motor, as a driver, transfers the recording paper in a transfer direction.
High speed recording is demanded for the inkjet recording apparatus, while downsizing the apparatus is also required. For realizing the high speed recording, the carriage and the recording paper must move at high speed. For instance, it is desirable to employ a high-power carriage driving motor and a high-power transferring motor. However, the high-power motor needs a larger outer diameter or a longer length along a rotating axis, so that a size of the motor is necessarily be bulky.
On the other hand, on a transfer path of the recording paper or in a travel space where the carriage reciprocates, no components should be placed. Thus, these motors must be placed outside of the transfer path and travel space, and a large additional space must be provided for disposing these motors. As a result, high-speed recording is achieved at the cost of increasing the size of the apparatus.
As such, the inkjet recording apparatus has encountered contradictory requirements, i.e., high-speed recording and downsizing.
Isn order to solve the problem of these contradictory requirements, the following structure is designed. The carriage and an ink-tank are coupled to each other with ink supplying tubes, and the ink-tank is disposed outside of the carriage. Ink in the ink-tank is supplied to recording heads of the carriage via the tubes. However, even for an apparatus with this structure, it is very difficult to dispose the tubes so that the ink can be supplied in a stable manner for recording at high-speed, e.g., ink ejecting frequency is not less than 18 kHz.
When these tubes are bent with a curvature as small as an electric wiring can be bent, the flowing path is bent and damaged. The smaller the diameter of the tube, the smaller the curvature that the tube can be bent. However, the resistance in the flowing path against the ink increases due to narrowing the diameter of the tube.
Therefore, these tubes are desirably disposed with rather larger curvatures, which, however, requires a larger space and results in a bulky apparatus.
Even if the tubes are disposed with rather larger curvatures, the carriage is placed at a distance from the ink-tank, so that the tubes must be long. This results in greater resistance from the flow-path against the flowing ink, so that the ink cannot be supplied in a stable manner. In addition to this, the distant placing of the ink-tank from the carriage invites a bulky apparatus. Further, narrower and longer tubes yield a greater flow path resistance against the flowing ink, which prevents high-speed printing.
The present invention addresses the problem discussed above, and aims to provide an inkjet recording apparatus in which the two contradictory requirements, i.e., high-speed recording and downsizing, are compatible.
The inkjet recording apparatus of the present invention comprises recording heads mounted to a carriage and ejecting plurality of colored inks, ink tanks for pooling ink of respective colors, and a plurality of ink supplying tubes for coupling the recording heads to ink tanks so that the ink of each color in the ink tanks is supplied to the recording heads, respectively. A specific color ink is ejected in a greater amount per unit time than other colored inks, and an ink supplying tube for the specific color supplies a greater amount than other tubes assigned to other colors.
Another inkjet recording apparatus of the present invention comprises, recording heads mounted to a carriage and ejecting a plurality of colored inks, ink tanks for pooling ink of respective colors; and a plurality of ink supplying tubes for coupling the recording heads to ink tanks so that the ink of each color in the ink tanks is the recording heads, respectively. A viscosity of a specific color of ink is greater than those of other colors of ink, and the ink supplying tube for the specific color supplies equal to or greater amount than the tubes assigned to other colors.
Still another inkjet recording apparatus of the present invention comprises a scanner having a carriage-driving-motor for reciprocating a carriage having recording heads in a scanning direction (X axis direction), and a transfer machine having a transfer motor for transferring a recording paper in a transfer direction (Y axis direction) perpendicular to the scanning direction. Both of the motors are at approximately the same place regarding an ink-ejecting-direction (Z axis direction). Actually, the motors are disposed at a height of the transfer-path of the recording paper, or the motors are disposed on the carriage side with respect to the transfer path.
Still further, another inkjet recording apparatus of the present invention comprises a carriage having recording heads and reciprocating in a scanning direction, ink tanks containing ink to be supplied to the recording heads, and ink supplying tubes routed from the carriage to the ink tanks via travel space for the carriage reciprocating, thereby coupling the carriage to the ink tanks. The inks ejected from the recording heads are attached to a recording paper transferred in a transfer direction perpendicular to a scanning line, thereby performing the recording.
Still another inkjet recording apparatus of the present invention comprises recording heads for ejecting different colored ink independently, a carriage having the recording heads and reciprocating in a scanning direction (X axis direction), a plurality of ink tanks aligned in the scanning direction and containing respective colors of ink to be supplied to the recording heads, ink supplying tubes routed from the carriage to the ink tanks via travel space for the carriage reciprocating, thereby coupling the carriage to the ink tanks, and a coupling section disposed on the ink tank side of the carriage travel space and bundling the ink supplying tubes. Among the plurality of ink tanks, the ink tank containing the ink of the highest viscosity is placed closest to the coupling section. The ink ejected from the recording heads is attached to a recording paper transferred in a transfer direction (Y axis direction) perpendicular to the scanning direction thereby performing the recording.
Still another inkjet recording apparatus of the present invention comprises recording heads for ejecting different colored inks independently, a carriage having the recording heads and reciprocating in a scanning direction (X axis direction), a plurality of ink tanks aligned in the scanning direction and containing respective colors of ink to be supplied to the recording heads, ink supplying tubes routed from the carriage to the ink tanks via travel space for the carriage reciprocating, thereby coupling the carriage to the ink tanks, and a coupling section disposed on the ink tank side of the carriage travel space and bundling the ink supplying tubes. Among the plurality of ink tanks, the tank containing the most consumed ink is placed closest to the coupling section. The ink ejected from the recording heads is attached to a recording paper transferred in a transfer direction (Y axis direction) perpendicular to the scanning direction, thereby performing the recording.
Still another inkjet recording apparatus of the present invention comprises recording heads for ejecting ink, a carriage having recording heads and for reciprocating in a scanning direction (X axis direction), ink tanks containing ink to be supplied to the recording heads, and ink supplying tubes for coupling the carriage to the ink tanks. The ink supplying tubes are coupled to a side of the carriage in a transfer direction (Y axis direction) perpendicular to the scanning direction, i.e., a side section of the carriage in Y direction. The ink supplying tube is also bowed toward a first side in the scanning direction (X axis direction) at a space adjacent to the carriage moving space on the side of Y direction. When the carriage is placed at the end of the first side of the scanning direction, an end position of the bowed section is placed at approximately the same position as the end of the first side in the scanning line, or the end position of the bowed section is placed on a second side from the end of the first side in X axis direction.
The present invention can provide inkjet recording apparatuses in which high-speed recording and downsizing of the apparatus are compatible thanks to the structures discussed above.